Electron transfer paths prevailing in hemoproteins will be elucidated. Solutions of model compounds will be prepared which mimic the sluggish redox reactivities of hemoglobin and myoglobin. Alternate synthetic models will be "tailor-made" which duplicate the rapid electron transfer capabilities of cytochrome c. Electrochemical, spectroscopic, magnetic resonance and calorimetric methodologies will be used for obtaining information on the relevant thermodynamics, hemochrome structures and stabilities, kinetics and mechanisms.